#include <iostream>
#include <cstdio>//c++风格的c语言头文件

int main()
{
    //c
    printf("hello printf->stdout\n");
    fprintf(stdout, "hello fprintf->stdout\n");
    fprintf(stderr, "hello fprintf->stderr\n");

    //c++
    std::cout << "hello cout->cout" << std::endl;
    std::cerr << "hello cerr->cerr" << std::endl;

}